Pneumatic energy absorbing seat assembly

ABSTRACT

A vehicle seat assembly includes a seat back shell having upper and lower ends, and a bracket mounted to the seat back shell having a slot formed therethrough. A substantially S-shaped flexible plate is positioned adjacent the seat back shell and slidable within the slot. A cushion is positioned adjacent the S-shaped flexible plate. At least one inflatable lumbar bladder is positioned between the shell and the flexible plate between the bracket and the lower end. At least one inflatable thoracic adjustment bladder is positioned between the shell and the flexible plate between the bracket and the upper end. The contour of the seat assembly is adjustable by inflating and deflating the lumbar and thoracic bladders. A head restraint system includes a damper mechanism positioned between the upper end of the shell and the head restraint for energy management in a high energy impact. Also provided is a cushion and trim assembly adapted for direct attachment to the flexible plate having a plurality of attachment apertures formed therein. The cushion and trim assembly includes trim flaps which are attachable to the attachment apertures, and the flexible plate is partially slidable within the bracket.

CROSS-REFERENCE TO RELATED APPLICATION

This invention is a continuation-in-part of U.S. Ser. No. 08/787,677,filed Jan. 23, 1997 entitled "Pneumatic Energy Absorbing Seat Assembly",now abandoned, and which is assigned to the assignee of the presentapplication and which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The present invention relates to a pneumatic energy absorbing seatassembly with a pneumatically adjustable seat back.

BACKGROUND ART

In a high energy impact, large impact forces may be delivered to theoccupant by the seat in a rearward impact. As the occupant is forcedagainst the seat, a large energy pulse may be experienced.

A particular safety problem may arise if the occupant has not properlyadjusted the head restraint system or if the seat back does not closelyand firmly support the entire spine during the impact. Undesirablespacing between the occupant and the seat back and head restraint mayallow the occupant to be propelled against the seat.

No known seat assembly exists which provides close and firm support ofthe entire spine for the occupant, provides an adjustable seat backcontour, and also manages energy in the head restraint in a high energyimpact. Accordingly, it is desirable to provide such a vehicle seatassembly with an adjustable contour to closely fit against the spine ofthe occupant while including an adjustable head restraint system withenergy management capability.

Typical seat assemblies also comprise a large number of components, andthe trim cover is typically pulled over the top of the seat like a sockfor covering the seat back. This assembly process is cumbersome andtime-consuming and results in expensive assembly. Accordingly, it isdesirable to provide a vehicle seat assembly with simplified trim coverattachment, and with reduced trim content and reduced part count.

DISCLOSURE OF THE INVENTION

As a result of Lear Corporation's continuing efforts to improve vehiclesafety, the present invention overcomes the above-referencedshortcomings of prior art seat assemblies by providing a pneumatic seatassembly in which the seat back and head restraint are pneumaticallyadjustable to closely fit the contour of the occupant's spine, and thehead restraint is provided with a damper mechanism(s) for managingenergy in a high energy impact.

More specifically, the present invention provides a vehicle seatassembly, comprising a seat back shell having upper and lower ends, anda bracket mounted to the seat back shell having a slot formed in thebracket. A flexible plate is positioned adjacent the seat back shell andis slidable within the slot. The plate includes first and secondsurfaces. A cushion is positioned against the first surface. At leastone inflatable lumbar bladder is positioned between the shell and theflexible plate between the bracket and the lower end. At least oneinflatable thoracic adjustment bladder is positioned between the shelland the flexible plate between the bracket and the upper end. In thisconfiguration, the contour of the seat assembly is adjustable byinflating and deflating the lumbar and thoracic bladders.

In the preferred embodiment, a head restraint member is secured to thesecond end of the flexible plate, whereby the head restraint member isadjustable forward and rearward in vehicle by inflating and deflatingthe at least one thoracic adjustment bladder. Additionally, a dampermechanism is positioned between the head restraint member and the upperend of the shell for damping movement of the head restraint member in ahigh energy impact.

In another embodiment, the present invention provides a flexible plate,trim cover and cushion assembly which is directly loadable onto to aseat back shell in a manner to reduce trim cover content, and tosimplify the assembly process. Because this assembly is attached to theseat back shell in a single step operation, the sock-type installationis eliminated, which reduces assembly time and assembly cost.

More specifically, this alternative embodiment comprises a seat backshell having upper and lower ends with a bracket mounted to the seatback shell, wherein the bracket has a bracket slot formed therethrough.A flexible plate is positioned adjacent the seat back shell and isslidable within the bracket slot. A trim cover is connected to theflexible plate and includes a cushion disposed therein.

Accordingly, an object of the present invention is to provide a seatback assembly with an adjustable contour for providing close and firmsupport of the entire spine in a high energy impact.

A further object of the present invention is to provide a vehicle seatassembly including a head restraint mechanism incorporating a damper formanaging energy in a high energy impact.

Another object of the present invention is to provide a vehicle seatassembly with reduced trim cover content and simplified assemblyprocedure.

The above objects and other objects, features, and advantages of thepresent invention are readily apparent from the following detaileddescription of the best mode for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematically arranged vertical cross-section of avehicle seat assembly in accordance with the present invention;

FIG. 2 shows an exploded perspective view of a flexible plate, cushionand trim cover assembly in accordance with the present invention; and

FIG. 3 shows a rear view of the flexible plate, cushion, and trim coverassembly shown in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a schematically arranged vertical cross-sectional view of avehicle seat assembly 10 in accordance with the present invention. Thevehicle seat assembly 10 includes a seat back shell 12 having upper andlower ends 14,16, respectively. A bracket 18 is mounted to the seat backshell 12 and includes a slot formed therethrough. The bracket 18 ispreferably a plastic member which spans the width of the shell 12.

A flexible plate 20 is positioned adjacent the seat back shell 12 and isslidable within the slot formed in the bracket 18. The plate 20 includesfirst and second surfaces 22,24, respectively. A cushion 26 ispositioned against the first surface 22 of the plate 20.

A plurality of inflatable lumbar bladders 28, 32 are positioned betweenthe shell 12 and the flexible plate 20, between the bracket 18 and thelower end 16 of the shell 12.

The flexible plate 20 is hinged to the lower end 16 of the shell 12 bythe hinge 36. Accordingly, when the inflatable lumbar bladders 28, 32are inflated or deflated, the flexible plate 20 is flexed and pivots atthe hinge 36, and the plate 20 slides within the bracket 18 such thatthe contour of the plate 20 is adjusted.

Similarly, an inflatable thoracic adjustment bladder 38 is positionedbetween the shell 12 and the flexible plate 20 between the bracket 18and the upper end 14 of the shell 12. A head restraint member 42 issecured to the upper end of the flexible plate 20, whereby the headrestraint member 42 is adjustable forward and rearward in vehicle byinflating and deflating the thoracic adjustment bladder 38. The headrestraint member 42 is preferably a blow-molded hollow plastic material.An energy absorbing foam 44 is secured to the head restraint member 42.

A damper mechanism 46 is secured between the upper end 14 of the shell12 and the head restraint member 42 for energy management in a highenergy impact. The damper 46 will allow gradual movement of the headrestraint member 42 with respect to the shell 12 as the thoracicadjustment bladder 38 is inflated or deflated for adjusting theforward/rearward position of the head restraint member 42 in thevehicle, and the damper 46 will be configured to dissipate headrestraint energy in a rearward impact to cushion the load transferbetween the occupant and the head restraint member 42.

Accordingly, in this configuration, the contour of the seat back may beadjusted by inflating or deflating the lumbar bladders 28, 32 and thethoracic bladder 38, to alter the curvature of the flexible plate 20 sothat the seat back and head restraint fit closely adjacent the spine andneck of the vehicle occupant.

The various bladders 28, 32, 38 may be filled with any inert gas, orfoam or liquid for additional energy management characteristics.

Additionally, the energy management aspects of the system may betailored to the occupant weight. For example, using a pneumatic seatlift mechanism, the weight of the occupant may be sensed and thisinformation may be used for adjusting the damper 46 and bladders 28, 32,38.

The combination of the energy absorbing foam 44, the cushion 26, thedamper 46, and bladders 28, 32, 38 will cooperate to manage energy ofthe occupant in a rearward impact and to prevent the occurrence ofundesirable spinal compression or large energy pulses.

Turning to FIG. 2, an alternative embodiment of the present invention isshown. In this embodiment, the flexible plate 60 (corresponding with theflexible plate 20 shown in FIG. 1) is adapted for mounting to a seatback shell, such as the shell 12 shown in FIG. 1. The flexible plate 60comprises a lower end portion 62 with snap features 64,66 for snap-inattachment to the lower end of a shell.

In order to facilitate bending of the flexible plate 60 as the seat backassembly is pneumatically flexed, as described previously,laterally-extending bend slots 68 are provided in the plate 60. In thisconfiguration, the bend slots 68 readily facilitate bending of the plate60.

The flexible plate 60 is further adapted to support the cushion and trimassembly 70. The cushion and trim assembly 70 comprises a cushion 72which is covered by a trim cover 74. The trim cover 74 includes aplurality of trim flaps 76 having attachment features 78 disposed atdistal ends thereof to facilitate attachment within the attachmentapertures 80 formed about the periphery of the flexible plate 60. Forattachment of the cushion and trim assembly 70 to the flexible plate 60,the trim flaps 76 are stretched around the back of the flexible plate60, and the attachment features 78 connect the distal ends of therespective trim flaps 76 within the corresponding attachment aperture80. The attachment features 78 could be J-clips, Hog rings, or any othercommonly known attachment feature in the seating art.

The flexible plate 60 further comprises a central portion 82 positionedbetween opposing apertures 84,86 formed in the flexible plate 60 forcooperation with the bracket 88, which corresponds to the bracket 18shown in FIG. 1. In this configuration, as the flexible plate 60 ispneumatically flexed as described above, the central portion 82 of theflexible plate 60 is free to slide within the bracket 88 to facilitatesuch flexing motion. The flexible plate 60 also includes a pair ofupstanding head rest support portions 90,92.

In an assembly operation, the cushion and trim assembly 70 would be laidface down, the bracket 88 would be installed over the central portion 82of the flexible plate 60, and finally, the flexible plate 60 and bracket88 would be laid over the top of the cushion and trim assembly 70. Thetrim flaps 76 would then be pulled around to the rear of the flexibleplate 60, and the attachment features 78 on the distal ends of the trimflaps 76 would be used to secure the trim flaps 76 within the apertures80 of the flexible plate 60. This entire assembly would then be loadedinto a seat back shell by attaching the bracket 88 to the seat backshell, and attaching the snap features 64,66 at the lower end portion 62of the flexible plate 60 to the lower end of the shell, such as at theattachment point 36 shown in FIG. 1. This load-type assembly operationeliminates the sock-type assembly operation of the prior art, andgreatly reduces trim content, because only the cushion 72 must becovered with trim, and the shell need not be trimmed.

The seat back shell, such as shell 12 shown in FIG. 1, may be formedsubstantially in the shape of a clam shell so that it wraps around theperipheral edges of the cushion and trim assembly 70 once the cushionand trim assembly 70 and flexible plate 60 have been installed andattached within the shell. The shell may comprise a grained plasticmaterial, or any other material, thus eliminating approximately half ofthe trim cover content. This assembly may also substantially reduceassembly time because the sock-type installation is very time-consumingand labor-intensive.

This assembly may also reduce seat assembly part count by eliminatingthe typical seat back frame and other structural components.

While the best mode for carrying out the invention has been described indetail, those familiar with the art to which this invention relates willrecognize various alternative designs and embodiments for practicing theinvention within the scope of the appended claims.

What is claimed is:
 1. A vehicle seat back assembly adapted forattachment to a seat back shell, comprising:a bracket adapted forattachment to the seat back shell, said bracket having a bracket slotformed therethrough; a flexible plate adapted for positioning adjacentthe seat back shell and having a portion slidably received within saidbracket slot; at least one thoracic bladder and at least one lumbarbladder positioned against the flexible plate, wherein said bracket slotis positioned between the thoracic bladder and lumbar bladder; a trimcover attached to the flexible plate; and a cushion disposed within thetrim cover.
 2. The vehicle seat assembly of claim 1, wherein saidflexible plate comprises a plurality of laterally extending bend slotsformed therein to facilitate bending of the flexible plate.
 3. Thevehicle seat assembly of claim 1, wherein said flexible plate comprisesa central portion positioned between opposing apertures formed in theplate for cooperation with the bracket, such that said central portionis slidable within said bracket slot.
 4. The vehicle seat assembly ofclaim 1, further comprising a plurality of attachment apertures formedin said flexible plate, and wherein said trim cover comprises aplurality of trim flaps attachable to said plurality of attachmentapertures for securing the cushion and trim cover to the flexible plate.5. The vehicle seat assembly of claim 1, wherein said flexible platecomprises a lower end having a snap feature adapted for attachment tothe lower end of said seat back shell.
 6. The vehicle seat assembly ofclaim 1, wherein said flexible plate comprises a pair of upstanding headrest support portions.
 7. A vehicle seat assembly, comprising:a seatback shell operative as a seat backframe and having upper and lower endsa bracket mounted to the seat back shell and having a bracket slotformed therethrough; a flexible plate positioned adjacent the seat backshell and having a portion slidably received within said bracket slot;said flexible plate having a plurality of attachment apertures formedtherein; and a cushion and trim assembly directly attached to theflexible plate, said cushion and trim assembly comprising a plurality oftrim flaps attachable to said plurality of attachment apertures forsecuring the cushion and trim assembly to the flexible plate.
 8. Avehicle seat assembly, comprising:a seat back shell operative as a seatbackframe and having upper and lower ends; a bracket mounted to the seatback shell and having a bracket slot formed therethrough; a flexibleplate positioned adjacent the seat back shell and having a portionslidably received within said bracket slot, said flexible platecomprising a pair of upstanding headrest support portions; and a cushionand trim assembly directly attached to the flexible plate.